Rendering only the highlights of an object in Cycles
You can emulate equivalent results with Cycles Ray Visibility flags for the lamp object.

To a similar result to highlights you can turn off all components except Glossy for your lamp object.



Have in mind that this will only work on objects with materials with some sort of glossy reflection component. Purely diffuse, transparent, refractive or translucent materials will likely become totally unaffected by that light siurce